/* taken from linux, and modified by zhenwei pi */
/* SPDX-License-Identifier: GPL-2.0 */
/*
 * NVMe over Fabrics TCP protocol header.
 * Copyright (c) 2018 Lightbits Labs. All rights reserved.
 */

#ifndef _LINUX_NVME_TCP_H
#define _LINUX_NVME_TCP_H

#include <nvme.h>

#define NVME_TCP_DISC_PORT 8009
#define NVME_TCP_ADMIN_CCSZ 8192
#define NVME_TCP_DIGEST_LENGTH 4
#define NVME_TCP_MIN_MAXH2CDATA 4096

enum nvme_tcp_pfv {
    NVME_TCP_PFV_1_0 = 0x0,
};

enum nvme_tcp_fatal_error_status {
    NVME_TCP_FES_INVALID_PDU_HDR = 0x01,
    NVME_TCP_FES_PDU_SEQ_ERR = 0x02,
    NVME_TCP_FES_HDR_DIGEST_ERR = 0x03,
    NVME_TCP_FES_DATA_OUT_OF_RANGE = 0x04,
    NVME_TCP_FES_R2T_LIMIT_EXCEEDED = 0x05,
    NVME_TCP_FES_DATA_LIMIT_EXCEEDED = 0x05,
    NVME_TCP_FES_UNSUPPORTED_PARAM = 0x06,
};

enum nvme_tcp_digest_option {
    NVME_TCP_HDR_DIGEST_ENABLE = (1 << 0),
    NVME_TCP_DATA_DIGEST_ENABLE = (1 << 1),
};

enum nvme_tcp_pdu_type {
    nvme_tcp_icreq = 0x0,
    nvme_tcp_icresp = 0x1,
    nvme_tcp_h2c_term = 0x2,
    nvme_tcp_c2h_term = 0x3,
    nvme_tcp_cmd = 0x4,
    nvme_tcp_rsp = 0x5,
    nvme_tcp_h2c_data = 0x6,
    nvme_tcp_c2h_data = 0x7,
    nvme_tcp_r2t = 0x9,
};

enum nvme_tcp_pdu_flags {
    NVME_TCP_F_HDGST = (1 << 0),
    NVME_TCP_F_DDGST = (1 << 1),
    NVME_TCP_F_DATA_LAST = (1 << 2),
    NVME_TCP_F_DATA_SUCCESS = (1 << 3),
};

/**
 * struct nvme_tcp_hdr - nvme tcp pdu common header
 *
 * @type:          pdu type
 * @flags:         pdu specific flags
 * @hlen:          pdu header length
 * @pdo:           pdu data offset
 * @plen:          pdu wire byte length
 */
struct nvme_tcp_hdr {
    __u8 type;
    __u8 flags;
    __u8 hlen;
    __u8 pdo;
    __le32 plen;
};

/**
 * struct nvme_tcp_icreq_pdu - nvme tcp initialize connection request pdu
 *
 * @hdr:           pdu generic header
 * @pfv:           pdu version format
 * @hpda:          host pdu data alignment (dwords, 0's based)
 * @digest:        digest types enabled
 * @maxr2t:        maximum r2ts per request supported
 */
struct nvme_tcp_icreq_pdu {
    struct nvme_tcp_hdr hdr;
    __le16 pfv;
    __u8 hpda;
    __u8 digest;
    __le32 maxr2t;
    __u8 rsvd2[112];
};

/**
 * struct nvme_tcp_icresp_pdu - nvme tcp initialize connection response pdu
 *
 * @hdr:           pdu common header
 * @pfv:           pdu version format
 * @cpda:          controller pdu data alignment (dowrds, 0's based)
 * @digest:        digest types enabled
 * @maxdata:       maximum data capsules per r2t supported
 */
struct nvme_tcp_icresp_pdu {
    struct nvme_tcp_hdr hdr;
    __le16 pfv;
    __u8 cpda;
    __u8 digest;
    __le32 maxdata;
    __u8 rsvd[112];
};

/**
 * struct nvme_tcp_term_pdu - nvme tcp terminate connection pdu
 *
 * @hdr:           pdu common header
 * @fes:           fatal error status
 * @fei:           fatal error information
 */
struct nvme_tcp_term_pdu {
    struct nvme_tcp_hdr hdr;
    __le16 fes;
    __le32 fei;
    __u8 rsvd[8];
};

/**
 * struct nvme_tcp_cmd_pdu - nvme tcp command capsule pdu
 *
 * @hdr:           pdu common header
 * @cmd:           nvme command
 */
struct nvme_tcp_cmd_pdu {
    struct nvme_tcp_hdr hdr;
    struct nvme_command cmd;
};

/**
 * struct nvme_tcp_rsp_pdu - nvme tcp response capsule pdu
 *
 * @hdr:           pdu common header
 * @hdr:           nvme-tcp generic header
 * @cqe:           nvme completion queue entry
 */
struct nvme_tcp_rsp_pdu {
    struct nvme_tcp_hdr hdr;
    struct nvme_completion cqe;
};

/**
 * struct nvme_tcp_r2t_pdu - nvme tcp ready-to-transfer pdu
 *
 * @hdr:           pdu common header
 * @command_id:    nvme command identifier which this relates to
 * @ttag:          transfer tag (controller generated)
 * @r2t_offset:    offset from the start of the command data
 * @r2t_length:    length the host is allowed to send
 */
struct nvme_tcp_r2t_pdu {
    struct nvme_tcp_hdr hdr;
    __u16 command_id;
    __u16 ttag;
    __le32 r2t_offset;
    __le32 r2t_length;
    __u8 rsvd[4];
};

/**
 * struct nvme_tcp_data_pdu - nvme tcp data pdu
 *
 * @hdr:           pdu common header
 * @command_id:    nvme command identifier which this relates to
 * @ttag:          transfer tag (controller generated)
 * @data_offset:   offset from the start of the command data
 * @data_length:   length of the data stream
 */
struct nvme_tcp_data_pdu {
    struct nvme_tcp_hdr hdr;
    __u16 command_id;
    __u16 ttag;
    __le32 data_offset;
    __le32 data_length;
    __u8 rsvd[4];
};

union nvme_tcp_pdu {
    struct nvme_tcp_icreq_pdu icreq;
    struct nvme_tcp_icresp_pdu icresp;
    struct nvme_tcp_cmd_pdu cmd;
    struct nvme_tcp_rsp_pdu rsp;
    struct nvme_tcp_r2t_pdu r2t;
    struct nvme_tcp_data_pdu data;
};

#endif /* _LINUX_NVME_TCP_H */
